"The accident happened on Tuesday night when the boat struck a rock in the dark. There are no signs or signals, which does nothing to help navigation," Mathieu Bela, district commissioner for North Ubangi, said.

Felix Ibula, a government spokesman, said: "We don't know at this time if some passengers, in addition to the 22 survivors, were able to save themselves."

Boats frequently sink in the country's network of lakes and rivers, often due to overloading. The country's waterways are also poorly surveyed, increasing the risk of accidents.

Most vessels do not comply with the basic safety requirements, lack proper navigation and emergency equipment such as life jackets, and have inadequate lighting.